Multiple synchrotron self-Compton modeling of gamma-ray flares in 3C 279

TL;DR

This paper presents a novel, self-consistent multiple inverse-Compton scattering model for gamma-ray flares in blazar 3C 279, explaining high-energy emission without relying on external seed photons.

Contribution

It introduces the first physical SSC model incorporating multiple inverse-Compton scatterings to explain gamma-ray flares in 3C 279.

Findings

Model accurately reproduces observed gamma-ray spectra during flares.

Multiple inverse-Compton scattering explains high-energy emission without external photon fields.

Analytic approach in Klein-Nishina limit is effective for spectral modeling.

Abstract

The correlation often observed in blazars between optical-to-radio outbursts and gamma-ray flares suggests that the high-energy emission region shall be co-spatial with the radio knots, several parsecs away from the central engine. This would prevent the important contribution at high-energies from the Compton scattering of seed photons from the accretion disk and the broad-line region that is generally used to model the spectral energy distribution of low-frequency peaking blazars. While a pure synchrotron self-Compton model has so far failed to explain the observed gamma-ray emission of a flat spectrum radio quasar like 3C 279, the inclusion of the effect of multiple inverse-Compton scattering might solve the apparent paradox. Here, we present for the first time a physical, self-consistent SSC modeling of a series of shock-waves in the jet of 3C 279. We show that the analytic description of the high-energy emission from multiple inverse-Compton scatterings in the Klein-Nishina limit can fairly well account for the observed gamma-ray spectrum of 3C 279 in flaring states.